Object-Oriented Programming

Java source files must use the .java extension as required by the Java compiler (javac). The .h extension is for C/C++ header files, and .class is the extension for compiled bytecode files produced by the compiler, not source files. Option C '>java' appears to be a typo or formatting error.

When Java source code is compiled, each class is converted to bytecode and stored in a separate file with the .class extension. This bytecode file contains instructions that the JVM can execute. The filename matches the class name (case-sensitive).

Java is Architectural Neutral because the compiled bytecode can run on any processor architecture. The JVM abstracts the underlying hardware, allowing the same bytecode to execute on different platforms without recompilation. This is a key feature that enables Java's 'write once, run anywhere' capability.

A constructor can be declared as private. This is a common design pattern in Java, frequently used to prevent instantiation or to implement the Singleton pattern.

Overloaded methods are completely independent methods that share the same name but have different parameter lists. They are free to have different access modifiers.

The Prototype pattern specifies object creation by cloning a prototypical instance instead of creating new instances from scratch. It's useful when creating a new object is expensive or complex, and you want to create new objects by copying this prototype and then modifying as needed.

The State pattern allows an object to change its behavior when its internal state changes, making it appear as if the object has changed its class. This is exactly what the question describes. Decorator adds responsibilities dynamically, Observer notifies dependents of state changes, and Strategy encapsulates interchangeable algorithms.

The State pattern allows an object to change its behavior when its internal state changes, making it appear as if the object has changed its class. This is exactly what the question describes. Decorator adds responsibilities dynamically, Observer notifies dependents of state changes, and Strategy encapsulates interchangeable algorithms.

The Adapter pattern converts the interface of a class into another interface clients expect. Option A should be 'Mediator' not 'Meditator' (typo). Template method defines skeleton of algorithm, Bridge separates abstraction from implementation. Adaptor (Adapter) is correct.

The Decorator pattern attaches additional responsibilities to an object dynamically, providing a flexible alternative to subclassing for extending functionality. Mediator defines how objects interact, Memento captures/restores state, and Strategy encapsulates interchangeable algorithms.

The Builder pattern separates the construction of a complex object from its representation, allowing the same construction process to create different representations. Prototype clones objects, Template method defines algorithm skeleton, and Momento (Memento) captures/restores state.

The Mediator pattern defines an object that encapsulates how a set of objects interact, promoting loose coupling by keeping objects from referring to each other explicitly and letting you vary their interaction independently. Visitor separates operations from object structure, Momento captures state, and Bridge separates abstraction from implementation.

In Hibernate ORM mapping, the mutable="false" attribute tells Hibernate that the entity's state never changes after initialization. This allows Hibernate to optimize performance by skipping dirty checking during flush operations for this entity. The ismutable attribute name doesn't exist in Hibernate.

Package overloading allows multiple subprograms with the same name if they differ in the number, type, or order of parameters (option E). Only local (private) subprograms within the package body or packaged subprograms in the specification can be overloaded (option A). Option B is false because subprograms cannot differ only in return type - the parameter signature must be different. Option C is false because identical parameters would create a duplicate, not an overload. Option D is false because the parameters must differ in some way.

Packages are designed to be shared - their contents (specification and body) can be used by many applications and users simultaneously (option D). Information hiding is achieved by declaring constructs in the package body only, making them private and inaccessible outside the package (option E). Packages cannot be nested (option A). Parameters are passed to procedures/functions within packages, not to packages themselves (option B). Packages are loaded once per session and cached, not reloaded each invocation (option C).